Simplify the following expression: $p = \dfrac{9}{2k + 5} \div \dfrac{10}{4k}$
Answer: Dividing by an expression is the same as multiplying by its inverse. $p = \dfrac{9}{2k + 5} \times \dfrac{4k}{10}$ When multiplying fractions, we multiply the numerators and the denominators. $p = \dfrac{ 9 \times 4k } { (2k + 5) \times 10}$ $p = \dfrac{36k}{20k + 50}$ Simplify: $p = \dfrac{18k}{10k + 25}$